namespace CSSharpPro._1030;
    public abstract class UserTest
    {
        public abstract void M1();
        public abstract void M2();
        public abstract void M3();
    }
    public class UserTestImpl : UserTest
    {
        public override void M1()
        {
            Console.WriteLine("实现 M1 方法");
        }
    
        public override void M2()
        {
            Console.WriteLine("实现 M2 方法");
        }
    
        public override void M3()
        {
            Console.WriteLine("实现 M3 方法");
        }
    }
